Among the semiconductor manufacturing equipments, there are ones that treat semiconductor wafers (hereinafter, referred to simply as wafers) by using chemicals or the like. As constructional members of such equipments, it is necessary to use ones which have chemical resistance and, at present, fluororesins, which have excellent chemical resistance, are used for such members.
However, the fluororesins have relatively low mechanical strength and, thus, when they are used as members for the semiconductor manufacturing equipments, it is necessary to take measures such as increasing the thickness of the fluororesins or reinforcing them with metals. Further, it is noted that, because the fluororesins have large coefficients of thermal expansion, thermal expansion has to be considered when they are used at high temperature.
Here, there is known a technique whereby a tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA) and polytetrafluoroethylene (PTFE) are made to contain carbon powder. If this technique is employed, thermal expansion can be suppressed by the carbon powder contained in these fluororesins.
Further, there is disclosed a technique whereby PTFE is made to contain carbon fiber (for example, see Japanese Patent Laid-Open Publication No. 2003-41083). When this technique is applied, it is possible not only to suppress thermal expansion but also to improve mechanical strength, due to the carbon fiber contained in the fluororesins.
However, in these techniques, the carbon powder and the like are exposed on the surface of PFA and PTFE. Therefore, when a member formed by a fluororesin containing such carbon powder and the like is used for a semiconductor manufacturing equipment, the carbon powder and the like become exposed to a chemical and the like. As a result, the carbon powder and the like might get dissolved in the chemical and the like to contaminate the wafer.